WASHINGTON — NASA is setting its sights on an asteroid as the next big landing destination for astronaut explorers, but senior officials with two of the agency’s international space station (ISS) partners say the Moon should be the goal.

The most senior of these officials is Vladimir Popovkin, head of the Russian federal space agency, Roscosmos, who said lunar missions are his agency’s top priority for human exploration. Speaking May 22 at a roundtable of government space agency leaders at the Global Space Exploration Conference here, Popovkin said the space station partners should use the outpost to test technologies needed for a return to the Moon.

“We would like to see this phenomenal lab as a test bed that would allow us an opportunity to verify and test lots of technology that will be essential for us to be able to step up and reach deeper space,” Popovkin said through an interpreter.

Given that Roscosmos — like the rest of the world’s space agencies — faces financial and technical constraints that rule out near-term exploration of Mars or an asteroid, “we arrive at the conclusion that the Moon is supposed to be the next target,” Popovkin said. “And when we talk about the Moon, we are not talking about replicating what mankind has already achieved … we are talking about establishing permanent station bases on the surface.”

Without explicitly endorsing Popovkin’s call for permanent Moon bases, a senior official from the Japan Aerospace Exploration Agency (JAXA) agreed that space agencies across the globe should look to send human explorers to the Moon, and to use the space station to test the technology needed to get there.

The Moon “is the next destination for mankind,” said Yuichi Yamaura, associate executive director of JAXA. “We have a responsibility to continue the ISS program. That may be in preparation for human activity on the Moon.”